1. Field of the Invention
The present invention relates to a head fitter to assist in fitting a head of a head with openings and attachments associated with those openings prior to attaching the head to the tank. More specifically the present invention is a head fitter for assisting in measuring and aligning a head so that holes can be cut in the head and so the appropriate flanges, valves, nozzles, or other attachments can be welded onto the head in association with the holes therein.
2. Description of the Related Art
The current procedure for fitting a tank head with openings for flanges, valves, etc. is to manually lift a head onto blocks so that the head can be strapped, i.e. the outside dimension or OD determined by measuring the outside circumference of the head. Once the OD has been determined, the OD is divided by 360 to arrive at the distance between each radial degree as measured on the outside circumference of the head.
Next, dividers are used to step off over the top of the head to mark the 0-180 degree line and to mark the 90-270 degree line. The 0-180 degree line is a straight line drawn over the top of the head so that the line passes through the 0 degree point on the outside perimeter of the head and through the 180 degree point on the outside perimeter of the head. This 0-180 degree line will pass through the center point of the head. Also a second line that passes through the center point of the head is drawn on the head. For example, if a 90-270 degree line is drawn as the second line over the top of the head, then this second line passes through the 90 degree point on the outside perimeter of the head and through the 270 degree point on the outside perimeter of the head. This second line will also pass through the center point of the head and will be perpendicular to the 0-180 degree line. The intersection of the 0-180 degree line and the 90-270 degree line is the center point of the head.
The next step is to lay out the location of each opening that is to be created in the head. This location consists of two components: the desired degree for the opening relative to the 0 degree point and the desired distance of the hole from the center point of the head, as measured along the desired radius.
For example, for an opening that are a given degree and a given distance from the center point of the head, the proper distance from the line is determined by multiplying the desired number of degrees from the 0 point on the outside perimeter of the head by the distance on the outside perimeter of the head previously calculated to represent one degree. The product of this calculation is the distance from the 0 point to the desired degree on the outside perimeter of the head. This distance is then measured and marked as the desired degree on the perimeter of the head and a radius is drawn from the marked desired degree to the center point of the head. Next, a level and measuring tape and a level are used to determine the point on the previously drawn desired degree radius line that is the desired distance from the center of the head, measuring perfectly horizontally. It is important that a level be employed to make sure that the desired distance is measured horizontally since the head is generally rounded in configuration and a measurement along the surface of the head would locate the opening incorrectly. A level is employed to mark the point on the desired degree radius line directly under the measuring tape. This process is repeated until all openings are marked.
The holes then are cut via a cutting torch. The holes are then beveled and a grinder is employed to clean the holes so attachments can be welded to the head around the holes. The attachments may be valves, flanges, nozzles, etc.
Before an attachment can be spot welded to the head in association with a hole, the attachment must be properly aligned with the hole. This alignment involves orienting the attachment perpendicular relative to the horizon, not relative to the curved surface of the head and involves positioning the attachment so that its nozzle, valve or flange is in the proper orientation relative to the hole. This later alignment is referred to in the trade a two holing the attachment since it generally involves orienting the even number of holes in the attachment's flange symmetrically with respect to a line on the head. For example, a flange that is two holed with respect to the 0-180 degree line on the head would have its flange openings symmetrically arranged with respect to a line that is parallel to the 0-180 degree line of the head and none of the flange openings would not on the line that is parallel to the 0-180 degree line.
In order to hold an attachment adjacent to a hole in the head in the proper vertical position and with the attachment two holed, it is first necessary to weld nozzle jacks onto the head. These nozzle jacks surround the hole and hold the attachment vertically over the hole in the proper two holed position while the attachment is tack welded to the head. Once the attachment has been tack welded to the head, the nozzle jacks are cut off of the head with a cutting torch and the place of attachment is ground smooth with a grinder. Once the nozzle jacks are removed, the attachment is welded completely to the head. This process is repeated until all the attachments have been properly positioned and welded to the head in association with the holes.
This current procedure for fitting a tank head is dangerous, labor intensive, costly, and involves a number of steps that can result in improper hole creation in the head and improper orientation of attachments to the head.
The present invention addresses these problems be providing a device for assisting in moving and rotating the head, assists in locating the location for holes, assists in cutting the holes in the head and assists in holding and positioning attachments relative to the holes in the head so that they can be tack welded to the head. By employing the present invention to fit tank heads, the job is a great deal less dangerous. Also by employing the present invention to fit tank heads, the job can be accomplished more quickly, with less labor, at less cost, and with fewer errors.
The present invention consists of a movable turntable that holds the tank head horizontally on its rotatable top surface. The movable turntable travels on rails so that is can move the tank head parallel with the ground and perpendicular to an overhead frame of the invention. The overhead frame straddles the turntable and the rails on which the turntable travels. The overhead frame is provided with frame rails on which a movable burner and a movable attachment holder travel. The movable burner can move along the frame rails to position it over the tank head and can be lowered and raised in order to cut holes in the head at desired locations on the head. The movable attachment holder can also move along the frame rails to position it and an attachment that is secured to the attachment holder over the tank head. The movable attachment holder can be lowered and raised in order to properly position attachments relative to the holes in the head so that the attachments can be tack welded to the head.